Patent GB-284296-A (GB)
Title: Electric remote control systems
IPC: H02J13/00
Filed: 1928-01-27
Abstract: 284,296. Compagnie des Telephones Thomson-Houston Soc. Anon. Jan. 27, 1927, [Convention date]. Selective distant control systems.-Relates to a remote system in which a step-by-step switch at the central station A is adapted to move in synchronism with step-by-step switches at one or more remote stations B. The invention resides in the provision at each of the stations of a multiwinding relay adapted to control the polarities impressed on a line by which synchronism of the stepping switches is maintained by actuation of stepping apparatus. The operation of a key 13 at the station A energizes relay 11 and earths the point MM. Relay 3 is operated by its lower winding energizing the stepping magnet 7 and moving the wipers one contact. The actuation of the interrupting switch 8 energizes relay 2 and locks relay 3 over its upper winding and closes the circuit of the stepping magnet of the time switch 6. Relay 2 in closing contact 21 earths the synchronizing line c operating relay 1 at both the central and remote stations. At the remote station actuation of relay 1 through contact 13 earths the point MM initiating a similar stepping operation and connecting the line c to earth. At the station A the time switch 6 maintains the stepping switch 7 de-energized and in closing contacts 65 actuates relay 4 which opens the starting contacts 42, 43 and locks itself energizing winding 28 of relay 2 and causes relay 5 to deenergize the time relay 6 which returns to normal. The stepping magnet 7 then moves the wipers to the second contacts, returning the relay 2 to zero by energizing winding 25 and removes earth from the wire c. When this has occurred at all stations relays 1 are de-energized, and de-energizing the windings 28 of relays 2 cause their operation to apply a battery through contact 23 to line c, operating relays 1 in the opposite direction. The stepping magnets are again energized and the wipers moved to the third contact and stepping proceeds in synchronism. Stopping and re-establishment of normal circuits. When the selectors reach contact 4 in the case of key 13 being operated, winding 27 is shortcircuited by contacts 24, 65 and selector II locking the. relay 2 and by maintaining the battery on the synchronizing line c locking the relays 1 at all the stations. Relays 5 are de-energized and the time-switches 6 actuated and close contacts 61, 62 of the actuating and signalling lines b, a. Relay 50 is energized at the remote station and through switch E operates the apparatus to be controlled. The interlock 23 energizes relay 52 and through selector IV connects line a to battery and actuates relav 10 at the central station to extinguish lamp V and light lamp R. In the arrangement shown, a flashing and alarm device 41 is provided so that the lighted lamp is flash lighted until the key 14 is actuated. At the central station relay 10 in addition opens the circuit of relay 11 breaking the starting circuit in 112 and in 111 opens winding 27 of relay 2, actuating this relay to release the selectors. On contact 50 winding 25 of relay 2 is energized, applying battery to the wire c and operating relay 1, thus energizing the stepping magnets and opening switches 8, returning relays 2 and 3 to normal and removing battery from the wire c. When this has occurred at all the stations relay 1 returns to normal, de-energizing relays 4. Safety arrangements. If the apparatus at the remote station fails to operate the time relay 6 opens at 64 the stopping circuit and stepping proceeds, allowing other contacts to execute other orders, but relay 11 remains energized until the operator returns key 13. If the selectors stop relay 5 is de-energized, the time switch operating and opening in 66 relay 3, thus returning relay 2 to normal while relay 4 is held by contact 8 and prevents a re-start of the apparatus till the selectors are returned to zero by the stepping magnet which is operated through contacts 33, 8 When all the remaining selectors are on zero relay 4 is de-energized and the operation re-started. If the selectors are placed out of phase all the selectors are returned to zero by a similar stepping operation. In the modification utilizing contact 6 of the selectors, no actuation is effected, but opening of the interlock 23 at the remote station signals the control station A which is provided with an alarm stopping key 34 similar to key 14, so that the operator can change the flashing signal to a constant one and prepare a flashing signal for the reverse operation. In the modification utilizing contact 5 of the selectors and actuating key 23, no interlocking arrangement is provided, so that if the controlled apparatus is released it is automatically re-engaged, since relay 60 is returned to neutral if the apparatus is released and operates relay 61 to close contact 612 to earth, the line c causing all the selectors to start up and restore the controlled apparatus. In the modification utilizing contacts 4 of the selectors and actuating key 13, interlocking is provided and the control effected by relay 50 operates electromagnetic switches E, M and relay 52 is energized by the interlock 23, which opens the switch E so that relay 52 remains energized while contact 503 is closed and prevents reengaging and signals the central station if the interlock opens by de-energizing 52 and ergizing relay 51. Re-engagement is effected by moving the key 13 to the disengaged position, thus energizing relay 12 and then to the engaged position to energize relay 11 and to repeat the signal. In the event of an immediate release, as when an automatic circuit breaker is operated on a short-circuit, the closing of the interlock operates relay 52 so that the engaged signal is given and a disengaged signal is initiated at the remote station when the selectors have returned to zero. The opening of the contact breaker is effected by key 13 at' the control station which in the disengaged position causes relay 50 at the remote station to open contact 501 in the circuit of the switch M. The opening of the interlock is signalled to the control station through relays 52, 10. In a modification, Figs. 5 and 6 (not shown), the lines a, bare dispensed with and signalling and actuation are effected by stepping the selectors on the required contact so that four contacts on the selector are used for one piece of apparatus. This arrangement, as with that shown in Figs. 3 and 4, may be used for signalling only or for actuating and signalling with or without interlocking. In a further modification, Figs. 7 and 8, a pre-selection relay system is employed so that a larger number of circuits is available. In these modifications, only two banks of wipers II, III are employed. Signalling is effected by relay 72 which is provided with additional contacts to mark either directly or through the pre-selector relay a contact on the stopping selector II so that at the actuating station A the closing of contact 62 of the time relay 6 through the actuating selector III energizes one winding of relay 30 to give the signal. The arrangement employing preselection relays permits a number of operations to be effected through a single contact on the selectors. In this the selectors are started bv the operation of key 13 closing contact 111. The closure of 112 marks contact 3 on stopping selector II common to all the circuits utilizing the pre-selection relay 80, so that through contact 62 and selector III the relay 80 is operated, locked and disconnects the remaining pre-selection relays from the battery. At the controlled station the pre-selection relay 90 is similarly operated and the operating system is connected through contacts 903 - - 906 to the selector contacts of which contacts 6, 7 serve to disengage the actuating and signalling circuits respectively and contacts 8, 9 serve to engage these circuits. The closure of contact 123 marks contact 8 of selector II to stop the selectors and at station B contact 8 of selector III operates relay 50 to effect the operation.